| Message ID | 20230927055246.121544-1-xuanzhuo@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [vhost] virtio_net: fix the missing of the dma cpu sync | expand |
On Wed, Sep 27, 2023 at 1:53 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote: > > Commit 295525e29a5b ("virtio_net: merge dma operations when filling > mergeable buffers") unmaps the buffer with DMA_ATTR_SKIP_CPU_SYNC when > the dma->ref is zero. We do that with DMA_ATTR_SKIP_CPU_SYNC, because we > do not want to do the sync for the entire page_frag. But that misses the > sync for the current area. > > This patch does cpu sync regardless of whether the ref is zero or not. > > Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") > Reported-by: Michael Roth <michael.roth@amd.com> > Closes: http://lore.kernel.org/all/20230926130451.axgodaa6tvwqs3ut@amd.com > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> Thanks > --- > drivers/net/virtio_net.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 98dc9b49d56b..9ece27dc5144 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -589,16 +589,16 @@ static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len) > > --dma->ref; > > - if (dma->ref) { > - if (dma->need_sync && len) { > - offset = buf - (head + sizeof(*dma)); > + if (dma->need_sync && len) { > + offset = buf - (head + sizeof(*dma)); > > - virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr, offset, > - len, DMA_FROM_DEVICE); > - } > + virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr, > + offset, len, > + DMA_FROM_DEVICE); > + } > > + if (dma->ref) > return; > - } > > virtqueue_dma_unmap_single_attrs(rq->vq, dma->addr, dma->len, > DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC); > -- > 2.32.0.3.g01195cf9f > >
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 98dc9b49d56b..9ece27dc5144 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -589,16 +589,16 @@ static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len) --dma->ref; - if (dma->ref) { - if (dma->need_sync && len) { - offset = buf - (head + sizeof(*dma)); + if (dma->need_sync && len) { + offset = buf - (head + sizeof(*dma)); - virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr, offset, - len, DMA_FROM_DEVICE); - } + virtqueue_dma_sync_single_range_for_cpu(rq->vq, dma->addr, + offset, len, + DMA_FROM_DEVICE); + } + if (dma->ref) return; - } virtqueue_dma_unmap_single_attrs(rq->vq, dma->addr, dma->len, DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
Commit 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") unmaps the buffer with DMA_ATTR_SKIP_CPU_SYNC when the dma->ref is zero. We do that with DMA_ATTR_SKIP_CPU_SYNC, because we do not want to do the sync for the entire page_frag. But that misses the sync for the current area. This patch does cpu sync regardless of whether the ref is zero or not. Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") Reported-by: Michael Roth <michael.roth@amd.com> Closes: http://lore.kernel.org/all/20230926130451.axgodaa6tvwqs3ut@amd.com Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/net/virtio_net.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)